Road Performance and Mechanism of Geopolymer Stabilized Gangue Mixtures
Two types of coal gangue were used to replace crushed stones,and the industrial solid waste-based geopolymer was used to replaced the cement in formulating geopolymer-stabilized coal gangue base course mixture.The road performance of the mixture was evaluated through mechanical performance tests and shrinkage tests,and the strength mechanism of the geopolymer-stabilized coal gangue mixture was analyzed by using microscopic experiments including XRD,TG-IR,and SEM.The results indicated that the road performance of the mixture containing mined gangue was good,whereas the mixture containing water-washed gangue showed rel-atively poor road performance.The interaction between geopolymer cementitious materials and coal gangue resulted in the formation of ettringite,C-A-S-H gel,and C-S-H gel,enhancing the mixture's strength.The significant differences in strength between the two types of coal gangue mixtures were attributed to the higher expansive soil content,organic matter content,and lower activity of washed gangue.